Folding wing airplane



Nov. 12, 1957 L. DE JEAN 2,812,911

FOLDING WING AIRPLANE Filed July so, 1953 's Sheets-Sheet 1 i 27% l2l4l 29 INVENTOR. LELAND DE JEAN ATTORNEY Nov. 12 1957 L. DE'JEAN 2,812,911

FOLDING WING AIRPLANE Filed July 30. 1953 3 Sheets-Sheet 2 INVENTOR. LELAND DE JEAN ATTORNEY Nov. 12, 1957 L. DE JEAN FOLDING WING AIRPLANE 3 Sheets-Sheet 3 Filed July so, 1953 v INVENTOK LELAND D JEAN.

ATTORNEY Unite This invention relates to folding wing airplanes and is particularly adapted to be used as a roadable airplane, wherein the Wings are folded after flight and the airplane is used on the highway.

The primary object of the invention is to provide a means of mounting the wings to the plane so that they can be folded within roadable limits.

In the accomplishing of this object, the wings are pivotally mounted in such a manner so that when they are folded back along the fuselage they will permit the required road clearances, and when they are in flying position they will have sufficient strength to insure safety in flight.

These and other incidental objects will be apparent in the drawings, specifications and claim.

Referring to the drawings:

Figure 1 is a plan view of my new and improved folding wing airplane, the wings in flight position.

Figure 2 is a plan view, illustrating the wings having been folded so that the plane can be driven on the highway.

Figure 3 is a side view of Figure 2.

Figure 4 is an enlarged fragmentary sectional view, taken on line 4-4 of Figure 1, illustrating how the wing is pivotally mounted to the main spar center section.

Figure 5 is an enlarged detail fragmentary sectional view, taken on line 5-5 of Figure 4, looking in the direction indicated.

Figure 6 is the top stationary hinge member connected to the top of the center main spar.

Figure 7 is the lower stationary hinged member connected to the lower side of the main spar.

Figure 8 is a plan fragmentary sectional view, taken on line 8-8 of Figure 5, looking down on to the lower hinged connection between the main spar center section and the wing spar.

Figure 9 is an inverted view of the upper hinge connection between the main spar center and the wing spar, taken on line 9-9 of Figure 5.

Figure 10 is a fragmentary end sectional view of the wing, taken on line 10-10 of Figure 1, illustrating the forward locking mechanism for holding the wing in flight position, together with a special doweling assembly for connecting the main spar center with the wing spar.

Figure 11 is a plan view of Figure 10, taken on line 11-11.

Figure 12 is a detail view, taken on line 12-12 of Figure 18 of the locking connection for holding the wing in flight position.

Figure 13 is a sectional view of the fuselage showing the wings in folded position, taken on line 13-13 of Figure 2.

Figure 14 is a detail illustrating how the wings are secured to the rudder assembly for holding them in folded position, taken on line 14-14 of Figure 13.

Figure 15 illustrates how the wing is connected to the fuselage while in folded position.

Figure 16 is a sectional view of the wing, taken on line States Patent O i 2,812,911 Patented Nov. 12, 1957 16-16 of Figure 1, but showing the ailerons in folded position preparatory to folding the wings towards the fuselage.

Figure 17 is a sectional view, taken on line 17-17 of Figure 2, showing the wings in folded position and illustrating how the fuselage is shaped to receive the wing.

Figure 18 is a sectional view through the main spar center section and wing stub, and an edge View of the folded wing, taken on line 18-18 of Figure 2.

Figure 19 is a sectional view, taken on line 19-19 of Figure 1, with the wings removed from the main spar center section.

Figure 20 is a fragmentary plan sectional view, taken on line 213-20 of Figure 4, parts broken away for convenience of illustration. This view illustrates the wing having been released and moving toward folded position.

Referring more specifically to the drawings:

My new and improved folding wing airplane consists of the fuselage A, wings B and a tail assembly C, together with the landing gear D. Referring particularly to Figures 4, 19 and 20, a main spar center section 1 is built into the fuselage A in the usual manner and extends beyond the said fuselage to the ends 5. An auxiliary spar 3 is also built into the fuselage, extending beyond the fuselage into the ends 4, referring to Figure 20.

The usual wing ribs 6 are connected to the spars 1 and 3 in the usual manner and covered by the usual metal skin 7. This provides solid stub wings or panels E extending on either side of the fuselage, as indicated particularly in Figures 1, 2, 3 and 20. The landing gear D is mounted to these stub wings and the fuselage on mobile supports mounted under the spar center sections in the usual manner.

The main wing spar is indicated by numeral 8. The usual ribs 6A extend rearwardly to the secondary spar 9 running the full length of the wing. A short auxiliary spar 10 is located in the leading edge of the wing. The object of which will be more fully described later.

I will now describe how the wings B are connected to the stub wings E. Referring particularly to Figures 4, 5, 8, 9 and 20, a hinge or pivot bolt 11 is secured to the main spar center section 1 by the brackets 12 and 13. The bracket 12 is fixedly secured to the top of the spar 1, best illustrated in Figures 5 and 20, by any well known means, as for instance the rivets 14. The bracket 13 is fixedly secured to the lower side of the spar 1 by the rivets 14, best illustrated in Figure 5. The bolt 11 may be held from turning within the bracket 12 by the squared portion 15 forming part of the bolt fitting Within a squared socket within the bracket 12.

Brackets 16 and 17 are fixedly secured to the inner end of the main spar 8 of the wing B. The bracket 16 is fixedly secured to the upper rail 18 of the spar 8, while the bracket 17 is secured to the lower rail 19 of the said spar by any suitable means, as for instance the bolts 20. Clamps 21 form part of the brackets 16 and 17 and are adapted to embrace the hinge or pivot bolt 11. These clamps are tightened down sufiiciently to eliminate play between the bolt and the clamps so that the wing will be perfectly rigid in regards to its pivot point.

The auxiliary spar 113 of the leading edge of the wing B is connected to the auxiliary center spar 3 by way of the fittings 22, which are fixedly secured to the spar 3 and the fitting 23, which is fixedly connected to the spar 10. When these two fittings come together a bolt 24 is entered through the holes 25 of the said fittings, as best illustrated in Figures 10, 11, 12 and 20.

Access to the bolt 24 is had through the skin 7 by way of the holes 26. To further assist in strengthening the wings, dowel pins 27 are attached to and form part of the main wing spar 8. These dowel pins have a base 27A formed thereon. This base is adapted to be fixedly secured to the upper rail 18 and the lower rails 19 of the main wing spar 8, shown particularly in Figures 4, and 11. These dowel pins enter the holes 28 formed Within the upper and lower rails of the main spar center section 1. These, dowel pins are relatively heavy asthey take considerable of the stress off of the hinge or pivot bolt 11 and its associated bracket. The reenforcing pad 28A is employed to strengthen the connection between the spar and the dowel pins, referring to Figures 10, 11 and 19.

' It will be noted that the hinge bolt 11 is positioned at an angle from the vertical and that this angle is approximately on a half-way point between the longitudinal axis of the plane and the chordwise axis of the wing when extended. The purpose of this Will be more apparent later on in the description of the folding of the wing. Fig. 16 shows a hinge 29' for aileron 29. The ailerons 29 and the flaps 30 are folded under the wing as illustrated particularly in Figures 13, 16 and 17. The said ailerons and flaps are held up under the wing by the bolts 32, Figure 16. The object of folding the ailerons and flaps is to provide sufficient road clearance.

In order to fold the wings to a compact position within the road limits, the bottom surfaces 100 of the fuselage is sloped from the point 33 to its lower bottom point 101.

In viewing Figures 13 and 17, it will be noted that the plane of the wing takes a position parallel to the sloping surfaces 100 and at an angle to the horizontal when folded under the fuselage. The reason for this is that when the wing is folded its rear edge 31 must pass under the fuselage beginning at the point 33, following down under the same until completely folded under the fuselage. This is the reason that the hinge or pivot bolt 11 must take an angle to the vertical axis causing the wing to slope as it comes under the fuselage to conform to the sloping bottom thereof, but at the same time this takes place the tip of the wing must lie in a horizontal plane. This is accomplished by giving the hinge or pivot bolt an angle rearwardly of the plane, as well as to the side.

When the wings are folded back their full distance, a hole 34 within the secondary spar 9 receives the supporting hook 35 which is supported by the framework of the fuselage at 36, referring to Figures 13 and This holds the wing up under the fuselage along its rear edge. The leading edge of thewing is supported to the vertical stabilizer 37 at 38 by way of the ears 39, which form part of the wing and part of the stabilizer, a bolt 40 passing therethrough with the usual wing nut.

I will now describe the method of folding the wings of my new and improved folding wing airplane. The controls of the ailerons 29 and the flaps are slackened, permitting the said ailerons and flaps to be folded to the position shown, particularly in Figure 16, at which time they are locked by the bolts 32 to the underside of the Wlng.

When the wing is to be folded, the bolt 24 is removed from the fittings 22 and 23 located in the leading edge of the wing by access to the openings 26, referring to Figures 10, 11, 12 and 20. This will permit the wing B to pivot back about the hinge or pivot bolt 11, the clamps 21 of the brackets 16 and 17 permitting this movement about the bolt.

Due to the angle of the bolt 11, the rear edge 31 of the Wings will lower down under the fuselage, beginning at the point 33, following the fuselage down its sloping bottom to the completed folded position as indicated in Figures 2, 3, l3 and 17. The hook will engage the hole 34 in the secondary spar 9 located in the rear edge 31 of the wing, referring to Figure 15 particularly. The ears 39 are then brought together and the bolt 40 inserted therethrough and locked under the vertical stabilizer 37, referring to Figures 13 and 14. The aircraft is then converted into a readable vehicle.

I have not attempted 'to show any detail of drives from the engine, as they may be of any suitable form, preferrably for selectively driving the propeller for flying or driving the landing wheels.

One person can convert this folding wing airplane from either flying or road operation, or vice versa. I have not described the folding of the wings, as it would be the exact reverse to the unfolding.

What is claimed is:

A convertible airplane comprising a fuselage including main and auxiliary spar center sections extending beyond the sides thereof, landing gear mounted under said spar center sections, stub wing portions carried by the extended end portions of said spar center sections, main wing portions each including main and auxiliary spar extension portions, said main wing portions being recessed at their inner ends near said main spar extension portions to fit around said stub wing portions with said auxiliary spar portions substantially in alignment and said main spar portions in overlapping relation, pivots carried by said main spar center sections adjacent each side of said fuselage, bearings on the inner ends of said main spar extension portions and mounted on said pivots to permit swinging of said main wing portions between operative positions fitting around said stub wing portions and extending outwardly from said fuselage and storage positions extending longitudinally of said fuselage and rearwardly of said stub wing portions, releasable connections on said auxiliary spar portions for securing said main wing portions in operative positions, and releasable connections on said fuselage and main wing portions for securing the latter in storage positions; the bottom surface of the fuselage being sloped on each side to receive the folded wings and be held in a compact position.

References Cited in the file of this patent UNITED STATES PATENTS 1,603,697 Klernm Oct. 19, 1926 1,793,056 Carns Feb. 17, 1931 2,572,421 Abel Oct. 23, 1951 2,674,422 Pellarini Apr. 6, 1954 FOREIGN PATENTS 11,961 Great Britain 1909 256,743 Great Britain Aug. 19, 1926 447,577 Great Britain May 21, 1936 452,883 Italy Nov. 8, 1949 484,622 Great Britain May 8, 1938 490,964 Great Britain Aug. 24, 1938 526,162 Great Britain Sept. 12, 1940 554,084 Great Britain June 18, 1943 557,257 Great Britain Nov. 12, 1943 

